A. Field of the Invention
This invention relates generally to computer databases and, more particularly, to methods and apparatus for providing object-based querying of a non-object-based database.
B. Description of the Related Art
Conventional, non-object-based database management systems (CDBMS) are widely used to store data. One popular type of a CDBMS, a relational database management system (RDBMS), stores data in the form of related tables. An RDBMS, however, is limited to relational (or tabular) data and does not have the sophistication required to manipulate more complex items such as objects associated with object-oriented programming languages. Some companies now provide an object-to-database mapping (ODM) system that converts objects to data and then stores the data in a CDBMS. With these systems, a software developer may to some extent integrate an object-oriented program with a CDBMS.
With both a CDBMS and an ODM system, however, data must be retrieved by using a standardized query language, such as SQL. Until now, therefore, software developers have not been able to take advantage of object-oriented programming languages to perform queries on data stored in a CDBMS. Instead, software developers have been required to formulate queries by using a standardized query language such as SQL. This approach limits software developers to the functions supported by SQL and does not allow them to take full advantages of the capabilities of object-oriented programming. Furthermore, in order to formulate SQL queries, software developers must learn how to map objects to the data stored in the DBMS.
There exists, therefore, a need for a system that allows software developers to formulate and perform object-based queries on data stored in a conventional, non-object-based DBMS.